1. Field of the Invention
The present invention relates to a plastic tube with a tubular tube body which is connected through a shoulder to a neck having an external thread and with a screw cap which can be screwed with an internal thread onto the external thread of the neck.
2. Description of the Related Art
A plastic tube of the above-described type is known from DE-PS 41 00 894. In addition to the screw connection of the cap to the external thread of the neck, a perforated diaphragm at the neck and a corresponding perforated element, for example, a truncated cone, are provided at the screw cap; however, these elements are not significant with respect to the present invention. This tube has the disadvantage of being of relatively complicated construction and another disadvantage is the fact that the tube body and the neck with the external thread are manufactured in one piece and, thus, of the same plastic material.
DE-OS 41 00 757 discloses a plastic tube which has a rectangular cross-section and is manufactured by blow molding, wherein the tube body also is integrally connected to the tube neck. A closure cap to be pressed on in the longitudinal direction of the tube can be connected to the tube neck by locking. Another disadvantage is the fact that this tube must be filled from that side which later is the side for dispensing the contents of the tube. This is relatively cumbersome and time-consuming In addition, there is the danger that air bubbles remain in the interior of the tube after filling the tube.
PCT/EP 91/02164 discloses a collapsible container for pasty products which has a shape similar to a tube. The body of this container is not rectangular in cross-section in the collapsed state. Two oppositely located side walls can be folded together in the manner of a harmonica. Seen in longitudinal direction of the container, one end of the container is closed permanently while the other end has a nozzle which can be closed by a screw cap. Also in this case, the body of the container and the part with the nozzle are manufactured in a single piece.
In DE-OS 41 00 757 as well as in PCT/EP 91/02164, the oppositely located side surfaces of the tube body are completely plane and parallel to each other. Consequently, a number of such tubes can be stacked easily and safely without requiring repacking. However, the features and effects thereof explained above with respect to the prior art do not suggest the subject matter of the present invention and the advantages achieved thereby.
Also, it should be mentioned that, in the prior art tubes, it must be ensured that the screw cap sealingly contacts the externally threaded neck either when the screw cap is automatically mounted by the manufacturer or when the screw cap is mounted manually. In this connection, there is the danger that the screw cap is screwed on too much or that the screw cap separates if the screw cap was screwed on to an insufficient extent.